Various fungicides have been tested to control Dutch elm disease in the American elm. The most well-known of these fungicides is Dupont's "Benonyl" or "Benlate" which has been tested for many years. Various injection techniques have been employed with this fungicide and it has been found to have limited effectiveness in inhibiting fungal development in diseased trees. An injection technique commonly called the Mauget Trunk Injection System where a plurality of spaced independent capsules containing the "Benlate" are circumferentially arranged around the tree trunk with spiles or conduits extending into the trunk for gravity flow of the "Benlate" into the tree has been employed. Although some successful tests have resulted from use of "Benlate", the chemical does not appear to be effective for widespread use under variable conditions and where the crown infection is substantially greater than 5%. It is believed that "Benlate" does not have sufficient solubility in the tree to provide effective distribution of the fungicide throughout the tree.